I had the same problem on my 2016 P1000, full windshield and back cab cover (not a full cab). I researched online for a cure, but got the same answers that I have read on this post. What I did is added the heat shield on the seat first. That helped the heat problem some... For the dust problem, I found that most of the dust was coming from around the bottom of the doors, and from behind the seat. So I used duct tape on the seat belt cracks, and then stuffed foam between the back of the beach seat. Around the door, I attached pipe insolation around the leading edges. This made a huge difference in the dust problem.